Dr. Georgios Tzimiropoulos

Position:

Past Member

Email:

Biography

I received the diploma degree in electrical and computer engineering from Aristotle University of Thessaloniki, Greece, in 2004 and the M.Sc. and Ph.D. degrees in signal processing and computer vision from Imperial College London, U.K., in 2005 and 2009, respectively. After the completion of my Ph.D., I was working as a Research and Development engineer with Imperial College/Selex Galileo. Since June 2010, I am a Research Associate in the Department of Computing at Imperial College working with Prof. Maja Pantic on face analysis.

Research Themes:

Face analysis:
Facial point tracking, Face registration

Biometrics & Behaviometrics:
Subspace learning for face recognition

Projects:

FROG

Publications

Journal articles

Subspace Learning from Image Gradient Orientations

G. Tzimiropoulos, S. Zafeiriou, M. Pantic. IEEE Transactions on Pattern Analysis and Machine Intelligence (accepted for publication). .

[supplemental data] [pdf] [bibtex] [endnote]

@article{tzimiro2012,
    author = {G. Tzimiropoulos and S. Zafeiriou and M. Pantic},
    journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence (accepted for publication)},
    title = {Subspace Learning from Image Gradient Orientations},
}

%0 Journal Article
%T Subspace Learning from Image Gradient Orientations
%A Tzimiropoulos, G.
%A Zafeiriou, S.
%A Pantic, M.
%J IEEE Transactions on Pattern Analysis and Machine Intelligence (accepted for publication)
%F tzimiro2012

Resources (Code)

http://ibug.doc.ic.ac.uk/resources/subspace-learning-image-gradient-orientations-igo-/

Subpixel registration with gradient correlation

G. Tzimiropoulos, V. Argyriou, T. Stathaki. IEEE Transactions on Image Processing. to appear. .

[bibtex] [endnote]

@article{tzimiropoulosSubpixel,
    author = {G. Tzimiropoulos and V. Argyriou and T. Stathaki},
    journal = {IEEE Transactions on Image Processing},
    note = {to appear},
    publisher = {IEEE},
    title = {Subpixel registration with gradient correlation},
}

%0 Journal Article
%T Subpixel registration with gradient correlation
%A Tzimiropoulos, G.
%A Argyriou, V.
%A Stathaki, T.
%J IEEE Transactions on Image Processing
%I IEEE
%F tzimiropoulosSubpixel
%O to appear

Regularized Kernel Discriminant Analysis With a Robust Kernel for Face Recognition and Verification

S. Zafeiriou, G. Tzimiropoulos, M. Petrou, T. Stathaki. IEEE Transactions on Neural Networks and Learning Systems (accepted for publication). 2011.

[pdf] [bibtex] [endnote]

@article{szafeirioutnn2011,
    author = {S. Zafeiriou and G. Tzimiropoulos and M. Petrou and T. Stathaki},
    journal = {IEEE Transactions on Neural Networks and Learning Systems (accepted for publication)},
    title = {Regularized Kernel Discriminant Analysis With a Robust Kernel for Face Recognition and Verification},
    year = {2011},
}

%0 Journal Article
%T Regularized Kernel Discriminant Analysis With a Robust Kernel for Face Recognition and Verification
%A Zafeiriou, S.
%A Tzimiropoulos, G.
%A Petrou, M.
%A Stathaki, T.
%J IEEE Transactions on Neural Networks and Learning Systems (accepted for publication)
%D 2011
%F szafeirioutnn2011

Robust FFT-Based Scale-Invariant Image Registration with Image Gradients

G. Tzimiropoulos, V. Argyriou, S. Zafeiriou, T. Stathaki. IEEE Transactions on Pattern Analysis and Machine Intelligence. 32(10): pp. 1899 - 1906, 2010.

[bibtex] [endnote]

@article{tzimiropoulos2010robust,
    author = {G. Tzimiropoulos and V. Argyriou and S. Zafeiriou and T. Stathaki},
    pages = {1899--1906},
    journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence},
    number = {10},
    publisher = {Published by the IEEE Computer Society},
    title = {Robust FFT-Based Scale-Invariant Image Registration with Image Gradients},
    volume = {32},
    year = {2010},
}

%0 Journal Article
%T Robust FFT-Based Scale-Invariant Image Registration with Image Gradients
%A Tzimiropoulos, G.
%A Argyriou, V.
%A Zafeiriou, S.
%A Stathaki, T.
%J IEEE Transactions on Pattern Analysis and Machine Intelligence
%D 2010
%V 32
%N 10
%I Published by the IEEE Computer Society
%F tzimiropoulos2010robust
%P 1899-1906

A unifying approach to moment-based shape orientation and symmetry classification

G. Tzimiropoulos, N. Mitianoudis, T. Stathaki. IEEE Transactions on Image Processing. 18(1): pp. 125 - 139, 2009.

[bibtex] [endnote]

@article{tzimiropoulos2009unifying,
    author = {G. Tzimiropoulos and N. Mitianoudis and T. Stathaki},
    pages = {125--139},
    journal = {IEEE Transactions on Image Processing},
    number = {1},
    publisher = {IEEE},
    title = {A unifying approach to moment-based shape orientation and symmetry classification},
    volume = {18},
    year = {2009},
}

%0 Journal Article
%T A unifying approach to moment-based shape orientation and symmetry classification
%A Tzimiropoulos, G.
%A Mitianoudis, N.
%A Stathaki, T.
%J IEEE Transactions on Image Processing
%D 2009
%V 18
%N 1
%I IEEE
%F tzimiropoulos2009unifying
%P 125-139

Robust recognition of planar shapes under affine transforms using principal component analysis

G. Tzimiropoulos, N. Mitianoudis, T. Stathaki. Signal Processing Letters, IEEE. 14(10): pp. 723 - 726, 2007.

[bibtex] [endnote]

@article{tzimiropoulos2007robust,
    author = {G. Tzimiropoulos and N. Mitianoudis and T. Stathaki},
    pages = {723--726},
    journal = {Signal Processing Letters, IEEE},
    number = {10},
    publisher = {IEEE},
    title = {Robust recognition of planar shapes under affine transforms using principal component analysis},
    volume = {14},
    year = {2007},
}

%0 Journal Article
%T Robust recognition of planar shapes under affine transforms using principal component analysis
%A Tzimiropoulos, G.
%A Mitianoudis, N.
%A Stathaki, T.
%J Signal Processing Letters, IEEE
%D 2007
%V 14
%N 10
%I IEEE
%F tzimiropoulos2007robust
%P 723-726

Conference articles

Robust and Efficient Parametric Face Alignment

G. Tzimiropoulos, S. Zafeiriou, M. Pantic. Proceedings of IEEE Int’l Conf. on Computer Vision (ICCV 2011) . pp. 1847 - 1854, Oral. November 2011.

[pdf] [bibtex] [endnote]

@inproceedings{tzimiroREPFAICCV2011,
    author = {G. Tzimiropoulos and S. Zafeiriou and M. Pantic},
    pages = {1847--1854},
    booktitle = {Proceedings of IEEE Int’l Conf. on Computer Vision (ICCV 2011) },
    month = {November},
    note = {Oral},
    title = {Robust and Efficient Parametric Face Alignment},
    year = {2011},
}

%0 Conference Proceedings
%T Robust and Efficient Parametric Face Alignment
%A Tzimiropoulos, G.
%A Zafeiriou, S.
%A Pantic, M.
%B Proceedings of IEEE Int’l Conf. on Computer Vision (ICCV 2011)
%D 2011
%8 November
%F tzimiroREPFAICCV2011
%O Oral
%P 1847-1854

Subspace Analysis Of Arbitrarily Many Linear Filter Responses with an application to Face Tracking

S. Zafeiriou, G. Tzimiropoulos, M. Pantic. Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on Computer Vision for Computer Games. Colorado Springs, USA, pp. 37 - 42, June 2011.

[pdf] [bibtex] [endnote]

@inproceedings{ZaferiouEtAlCVPRW2011,
    author = {S. Zafeiriou and G. Tzimiropoulos and M. Pantic},
    pages = {37--42},
    address = {Colorado Springs, USA},
    booktitle = {Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on Computer Vision for Computer Games},
    month = {June},
    title = {Subspace Analysis Of Arbitrarily Many Linear Filter Responses with an application to Face Tracking},
    year = {2011},
}

%0 Conference Proceedings
%T Subspace Analysis Of Arbitrarily Many Linear Filter Responses with an application to Face Tracking
%A Zafeiriou, S.
%A Tzimiropoulos, G.
%A Pantic, M.
%B Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on Computer Vision for Computer Games
%D 2011
%8 June
%C Colorado Springs, USA
%F ZaferiouEtAlCVPRW2011
%P 37-42

Sparse Representations of Image Gradient Orientations for Visual Recognition and Tracking

G. Tzimiropoulos, S. Zafeiriou, M. Pantic. Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on CVPR for Human Behaviour Analysis. Colorado Springs, USA, pp. 26 - 33, June 2011.

[pdf] [bibtex] [endnote]

@inproceedings{TzimiropoulosEtAlCVPR2011,
    author = {G. Tzimiropoulos and S. Zafeiriou and M. Pantic},
    pages = {26--33},
    address = {Colorado Springs, USA},
    booktitle = {Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on CVPR for Human Behaviour Analysis},
    month = {June},
    title = {Sparse Representations of Image Gradient Orientations for Visual Recognition and Tracking },
    year = {2011},
}

%0 Conference Proceedings
%T Sparse Representations of Image Gradient Orientations for Visual Recognition and Tracking
%A Tzimiropoulos, G.
%A Zafeiriou, S.
%A Pantic, M.
%B Proceedings of IEEE Int’l Conf. Computer Vision and Pattern Recognition (CVPR-W’11), Workshop on CVPR for Human Behaviour Analysis
%D 2011
%8 June
%C Colorado Springs, USA
%F TzimiropoulosEtAlCVPR2011
%P 26-33

Audiovisual classification of vocal outbursts in human conversation using long-short-term memory networks

F. Eyben, S. Petridis, B. Schuller, G. Tzimiropoulos, S. Zafeiriou. Proceedings of IEEE Int’l Conf. Acoustics, Speech and Signal Processing (ICASSP’11). Prague, Czech Republic, pp. 5844 - 5847, May 2011.

[pdf] [bibtex] [endnote]

@inproceedings{EybenEtAlICASSP2011,
    author = {F. Eyben and S. Petridis and B. Schuller and G. Tzimiropoulos and S. Zafeiriou},
    pages = {5844--5847},
    address = { Prague, Czech Republic},
    booktitle = { Proceedings of IEEE Int’l Conf. Acoustics, Speech and Signal Processing (ICASSP’11)},
    month = {May},
    title = {Audiovisual classification of vocal outbursts in human conversation using long-short-term memory networks},
    year = {2011},
}

%0 Conference Proceedings
%T Audiovisual classification of vocal outbursts in human conversation using long-short-term memory networks
%A Eyben, F.
%A Petridis, S.
%A Schuller, B.
%A Tzimiropoulos, G.
%A Zafeiriou, S.
%B Proceedings of IEEE Int’l Conf. Acoustics, Speech and Signal Processing (ICASSP’11)
%D 2011
%8 May
%C Prague, Czech Republic
%F EybenEtAlICASSP2011
%P 5844-5847

Fast and Robust Appearance-based Tracking

S. Liwicki, S. Zafeiriou, G. Tzimiropoulos, M. Pantic. Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG'11). Santa Barbara, CA, USA, pp. 507 - 513, March 2011.

[pdf] [bibtex] [endnote]

@inproceedings{StephanEtAlFG2011,
    author = {S. Liwicki and S. Zafeiriou and G. Tzimiropoulos and M. Pantic},
    pages = {507--513},
    address = {Santa Barbara, CA, USA},
    booktitle = {Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG'11)},
    month = {March},
    title = {Fast and Robust Appearance-based Tracking},
    year = {2011},
}

%0 Conference Proceedings
%T Fast and Robust Appearance-based Tracking
%A Liwicki, S.
%A Zafeiriou, S.
%A Tzimiropoulos, G.
%A Pantic, M.
%B Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG?11)
%D 2011
%8 March
%C Santa Barbara, CA, USA
%F StephanEtAlFG2011
%P 507-513

Principal Component Analysis of Image Gradient Orientations for Face Recognition

G. Tzimiropoulos, S. Zafeiriou, M. Pantic. Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG'11). Santa Barbara, CA, USA, pp. 553 - 558, March 2011.

[pdf] [bibtex] [endnote]

@inproceedings{tzimiropoulosEtAlFG2011,
    author = {G. Tzimiropoulos and S. Zafeiriou and M. Pantic},
    pages = {553--558},
    address = {Santa Barbara, CA, USA},
    booktitle = {Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG'11)},
    month = {March},
    title = {Principal Component Analysis of Image Gradient Orientations for Face Recognition},
    year = {2011},
}

%0 Conference Proceedings
%T Principal Component Analysis of Image Gradient Orientations for Face Recognition
%A Tzimiropoulos, G.
%A Zafeiriou, S.
%A Pantic, M.
%B Proceedings of IEEE International Conference on Automatic Face and Gesture Recognition (FG?11)
%D 2011
%8 March
%C Santa Barbara, CA, USA
%F tzimiropoulosEtAlFG2011
%P 553-558

Other publications

Bidirectional relighting for 3D-aided 2D Face Recognition

G. Toderici, G. Passalis, S. Zafeiriou, G. Tzimiropoulos, M. Petrou, T. Theoharis, I. Kakadiaris. Computer Vision and Pattern Recognition (CVPR), 2010 IEEE Conference on. IEEE, pp. 2721 - 2728, 2010.

[bibtex] [endnote]

@conference{toderici2010bidirectional,
    author = {G. Toderici and G. Passalis and S. Zafeiriou and G. Tzimiropoulos and M. Petrou and T. Theoharis and I. Kakadiaris},
    pages = {2721--2728},
    booktitle = {Computer Vision and Pattern Recognition (CVPR), 2010 IEEE Conference on},
    organization = {IEEE},
    title = {Bidirectional relighting for 3D-aided 2D Face Recognition},
    year = {2010},
}

%0 Journal Article
%T Bidirectional relighting for 3D-aided 2D Face Recognition
%A Toderici, G.
%A Passalis, G.
%A Zafeiriou, S.
%A Tzimiropoulos, G.
%A Petrou, M.
%A Theoharis, T.
%A Kakadiaris, I.
%D 2010
%F toderici2010bidirectional
%P 2721-2728

Fast wavelet-based pansharpening of multi-spectral images

N. Mitianoudis, G. Tzimiropoulos, T. Stathaki. Imaging Systems and Techniques (IST), 2010 IEEE International Conference on. IEEE, pp. 11 - 16, 2010.

[bibtex] [endnote]

@conference{mitianoudis2010fast,
    author = {N. Mitianoudis and G. Tzimiropoulos and T. Stathaki},
    pages = {11--16},
    booktitle = {Imaging Systems and Techniques (IST), 2010 IEEE International Conference on},
    organization = {IEEE},
    title = {Fast wavelet-based pansharpening of multi-spectral images},
    year = {2010},
}

%0 Journal Article
%T Fast wavelet-based pansharpening of multi-spectral images
%A Mitianoudis, N.
%A Tzimiropoulos, G.
%A Stathaki, T.
%D 2010
%F mitianoudis2010fast
%P 11-16

A new penalty term for the BIC with respect to speaker diarization

T. Stafylakis, G. Tzimiropoulos, V. Katsouros, G. Carayannis. Acoustics Speech and Signal Processing (ICASSP), 2010 IEEE International Conference on. IEEE, pp. 4978 - 4981, 2010.

[bibtex] [endnote]

@conference{stafylakis2010new,
    author = {T. Stafylakis and G. Tzimiropoulos and V. Katsouros and G. Carayannis},
    pages = {4978--4981},
    booktitle = {Acoustics Speech and Signal Processing (ICASSP), 2010 IEEE International Conference on},
    organization = {IEEE},
    title = {A new penalty term for the BIC with respect to speaker diarization},
    year = {2010},
}

%0 Journal Article
%T A new penalty term for the BIC with respect to speaker diarization
%A Stafylakis, T.
%A Tzimiropoulos, G.
%A Katsouros, V.
%A Carayannis, G.
%D 2010
%F stafylakis2010new
%P 4978-4981

FFT-based estimation of large motions in images: A robust gradient-based approach

G. Tzimiropoulos, V. Argyriou, T. Stathaki. Acoustics, Speech and Signal Processing, 2009. ICASSP 2009. IEEE International Conference on. IEEE, pp. 969 - 972, 2009.

[bibtex] [endnote]

@conference{tzimiropoulos2009fft,
    author = {G. Tzimiropoulos and V. Argyriou and T. Stathaki},
    pages = {969--972},
    booktitle = {Acoustics, Speech and Signal Processing, 2009. ICASSP 2009. IEEE International Conference on},
    organization = {IEEE},
    title = {FFT-based estimation of large motions in images: A robust gradient-based approach},
    year = {2009},
}

%0 Journal Article
%T FFT-based estimation of large motions in images: A robust gradient-based approach
%A Tzimiropoulos, G.
%A Argyriou, V.
%A Stathaki, T.
%D 2009
%F tzimiropoulos2009fft
%P 969-972

A Frequency Domain Approach to Roto-translation Estimation using Gradient Cross-Correlation

G. Tzimiropoulos, V. Argyriou, T. Stathaki. Citeseer, 2008.

[bibtex] [endnote]

@conference{tzimiropoulos2008frequency,
    author = {G. Tzimiropoulos and V. Argyriou and T. Stathaki},
    publisher = {Citeseer},
    title = {A Frequency Domain Approach to Roto-translation Estimation using Gradient Cross-Correlation},
    year = {2008},
}

%0 Journal Article
%T A Frequency Domain Approach to Roto-translation Estimation using Gradient Cross-Correlation
%A Tzimiropoulos, G.
%A Argyriou, V.
%A Stathaki, T.
%D 2008
%I Citeseer
%F tzimiropoulos2008frequency

Symmetry detection using frequency domain motion estimation techniques

G. Tzimiropoulos, V. Argyriou, T. Stathaki. Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE International Conference on. IEEE, pp. 861 - 864, 2008.

[bibtex] [endnote]

@conference{tzimiropoulos2008symmetry,
    author = {G. Tzimiropoulos and V. Argyriou and T. Stathaki},
    pages = {861--864},
    booktitle = {Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE International Conference on},
    organization = {IEEE},
    title = {Symmetry detection using frequency domain motion estimation techniques},
    year = {2008},
}

%0 Journal Article
%T Symmetry detection using frequency domain motion estimation techniques
%A Tzimiropoulos, G.
%A Argyriou, V.
%A Stathaki, T.
%D 2008
%F tzimiropoulos2008symmetry
%P 861-864

An Affine Invariant Function using PCA Bases with an Application to Within-Class Object Recognition

G. Tzimiropoulos, N. Mitianoudis, T. Stathaki. Acoustics, Speech and Signal Processing, 2007. ICASSP 2007. IEEE International Conference on. IEEE, 1: 2007.

[bibtex] [endnote]

@conference{tzimiropoulos2007affine,
    author = {G. Tzimiropoulos and N. Mitianoudis and T. Stathaki},
    booktitle = {Acoustics, Speech and Signal Processing, 2007. ICASSP 2007. IEEE International Conference on},
    organization = {IEEE},
    title = {An Affine Invariant Function using PCA Bases with an Application to Within-Class Object Recognition},
    volume = {1},
    year = {2007},
}

%0 Journal Article
%T An Affine Invariant Function using PCA Bases with an Application to Within-Class Object Recognition
%A Tzimiropoulos, G.
%A Mitianoudis, N.
%A Stathaki, T.
%D 2007
%V 1
%F tzimiropoulos2007affine